France's most recognisable landmark, the iron Eiffel Tower erected in 1889, has seen its iconic frame festooned with many different decorations and objects over the years for various celebrations. Its latest addition is a little more subtle -- and maybe a little more in keeping with the tower's original purpose as a monument to human ingenuity and artistry.

Turbine installation.Photo by UGE

As part of a major renovation and upgrade to the tower's first floor, the Société d'Exploitation de la Tour Eiffel will be adding a variety of sustainability features -- the first of which is a pair of VisionAIR5 wind turbines designed by renewable energy specialist Urban Green Energy.

The two vertical-axis turbines have been installed on the tower's second level, about 122 metres (400ft) from the ground -- a position that maximises wind capture. The turbines have been specially painted so as to blend in with the tower, and produce virtually no sound. They can also capture wind from any direction, producing, between them, a total of 10,000kWh per year -- enough to power the tower's first floor.

"The Eiffel Tower is arguably the most renowned architectural icon in the world, and we are proud that our advanced technology was chosen as the Tower commits to a more sustainable future," said UGE CEO Nick Blitterswyk. "When visitors from around the world see the wind turbines, we get one step closer to a world powered by clean and reliable renewable energy."

There was no environmental benchmark the tower was required to meet; however, the SETE wishes to reduce the tower's environmental impact by 25 percent as part of the City of Paris Climate Plan. It is funding the entire €30 million cost of the renovation -- which includes cosmetic and safety upgrades -- itself.

Other sustainable measures to be introduced to the Eiffel Tower include LED lighting, solar panels, a rainwater collection system and high-power heat pumps.